Charles n



(No Model.)

1 G. N. HAMMOND.

INSULATOR.

Patented Dec. 26, 1893.

UNITED STATES PATENT OFFICE.

CHARLES N. HAMMOND, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE HAMMOND CLEAT AND INSULATOR COMPANY, OF SAME PLACE.

INSULATOR.

SPECIFICATION forming part of Letters Patent No. 511,612, dated December 26, 1893.

Application filedApril 12, 1893, Serial No. 470,019- (No model.)

To all whom it may concern.-

Be it known that 1, CHARLES N. HAMMOND, a citizen of the United States,residing at Boston, in the county of Suffolk and State of Massachusetts,have invented certain newand useful Improvements in Insulators, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has for its object to provide an improved insulator for electric wires.

My invention relates more particularly to insulators for indoor construction such as are employed in supporting and insulating the wires which are carried through buildings and the like. Itis desirable that insulators employed for this purpose should be of high insulative quality, should be strong and durable, and of tasteful appearance and they should be so constructed that the wires may be readily placed therein or removed therefrom. These objectsI attain by means of the insulator hereinafter more fully described and the novel features of which are pointed out in the claims which are appended hereto.

I have shown my improved device in the accompanying drawings, and will refer to said drawings in the following description.

In the drawings, Figures 1 and 2 are respectively a side view and plan of my insulator adapted to receive one wire. Figs. 3 and 4 are similar views of a two wire insulator, and Figs. 5 and 6 are similar views of a three wire insulator, all embodying my invention. Fig. 7 is a section on line 77 Fig. 6.

The insulator maybe made of anysuitable insulating material. I prefer, however, to make it from porcelain which is first molded to shape and then baked or fired in the wellknown manner.

The exterior shape or contour of the insulater is not essential. I prefer, however, the general shape shown in the drawings which, as will be obvious, will vary somewhat as the size of the insulator varies, and its capacity to carry one, two or more wires. The opening 7 to receive the wire is shown at A, said opening being curved and formed by two slightly tapering or inclined walls, so that the top of the opening which first receives the wire, when it is put in place, is somewhat wider than the bottom thereof. This facilitates the insertion of the wire. The retaining point b which forms one side of the opening A is provided with an over-hang so that when the wire is pushed into the opening A to the bottom of the same it may be straightened partially, lying in part under the over-hang b and is thus prevented from being accidentally displaced. The wire can only be withdrawn from the insulator by bending it somewhat and then lifting it out of the opening A.

In order to provide for the making of the over-hang at the point I) the body of the insulator underneath said pointis provided with an aperture a see Fig. 7, through which a post or upright of the mold may pass, to serve as a support upon which the material of the over-hang may be molded when the insulator is being formed. By this arrangement the body of the insulator is not weakened to any material extent by the opening for the projection from the mold, as is the case when the over-hang is on the opposite wall of the opening A at the point marked d. In the latter case, the openings for the posts or uprights of the mold upon which the over-hang rests while it is being formed are at the outside of the insulator and on either side thereof and these openings I have found materially weaken the insulator and in case it is slightly warped in baking have a tendency to cause it to break transversely when it is being screwed firmly into position on the wall. By the employment of a central over-hang equal efficiency is obtained, sharp corners are avoided which tend to wear the wire covering and the strength of the body of the insulator is not impaired. It will be noted that the curved wall of one side of the opening A is of less height than the wall on the opposite side and this facilitates the insertion of the wire.

The insulator is secured in place by one or more screws which pass vertically through it and for the reception of which holes I) are provided as shown.

In the manufacture of these insulators from material such as porcelain for example, which requires to be baked or fired the process of firing tends to cause the material to warp so that it frequently happens that the back or bottom of the insulator is not perfectly level or flat but is bowed up somewhat in the middle. In such case when the insulator is placedagainst the wall it will bear onthe wall only at the ends'and the screwing home of the securing screws will crack the insulator crosswise. It is desirable that the back or bottom of the insulator should not bear on the wall at the ends to an yg'reater degree than throughout the central-portions, and unlessit is absolutely flat, a condition which is difficult to obtain, it should bear rather more at the points where the screws pass through it so that there will be no danger of. bringing the pressure of the screws on the insulator in such a way as to cause it to break; To pro-" vide for this I bevel the bottom of the ins,u-' lator at the ends slightly as shown at f and the-centralportion of the insulator vbetween the end partsf may be slightly cutaway, if desired, vas shown at, g. The insulator isstrong enough throughout thiscentral portion to permit of its being somewhat out awayas shown and the cutting away saves a slight amount of stock. ,Itlwill be noted lthatlthe' ends of the walls on one .side. of the openings a are slightly inclined as shownat ht'in the same way as is thewall itself throughout its Whole extent v but the incline isisoinewhat greater atthe ends. This is anadvantage in the insertionof the wire and tends toprevent its covering being frayed or damagedby inserting it in orwithdrawing it froin the insulator. 4

What I claim is?- 1. An insulator for electric wires having andfor the purposes set forth.

'3. An insulator for electric Wires having one or more openings to receive the wire, said openings having an over-hangon one side thereof located over the central portion or body. of the insulator whereby the aperture for that portion of the mold which supports the over-hangin mQldingis in the central portion of the bodyof the insulator, substantiallyjasiand; for the. purposes set forth.

4. Anfinsulatonfor electric wireshaving I one or more openings to: .receivethe wire and having the; bottotn thereof beveledat either endrwhereby thecentraL portions of, the insulatorwill con c to a bearing on its support when theinsulator is secured in position beof, substantially fore the end; portions .t'her as, and for the purposes set forth.

n t s m her o f xm si natur in P esenc 9 tw W t e se onARLEs 7N. HAMMOND.

NVitnesses:

WM- QL QD RoBnnT WALLACE. 

